Dimensionless form for Goodwin's equation of business cycle

We have conducted numerically a comparative analysis of two models of the business cycle proposed by R. Goodwin, Econometrica, 19, 1-17 (1951): in form of the neutral differential equation with fixed delay and in form of the second order nonlinear ordinary differential equation. Both models demonstrate the possibility of oscillations of income (so-called Goodwin's oscillations). We have shown that for these models the excitation conditions for Goodwin's oscillations and the some its properties may be very different.